Garbage grinder and disposer



Filed June 10, 1955 is I 7 CECIL M- W/LDER,

INVENTOR.

ok y'wb ATTORNEY;

United States Patent ice GARBAGE GRINDER AND DISPOSER Cecil M. Wilder,Whittier, Califl, assignor, by mesne assignments, to Pump SuppliersInc., Pico, Calif., a corporation of California Application June 10,1955, Serial No. 514,525

2 Claims. (Cl. 241-257) This invention relates to garbage disposers ofthe wellknown type having means for grinding garbage in the presence ofa stream of water and flushing the ground garbage through an outletwhich is connected to a sewer line. The general object of the inventionis to provide an improved garbage grinder of this general class.

A specific object of the invention is to provide a garbage disposerhaving improved grinding means adapted to chop fibrous material as wellas to pulverize pulpy material of a non-fibrous character. Inthis-respect, the conventional garbage grinders now available areuniversally subject to failure in the presence of any substantialquantity of fibrous material such as corn husks, artichoke hulls, andthe like. The housewife, discovering that such material becomes cloggedin the grinding mechanism and ultimately stops the operation of thegrinder, learns to dispose of these materials through other channels,and avoids any attempt to dispose of them through her garbage grinder.The present invention solves this problem by providing grinder mechanismwhich, in addition to more or less conventional grinding jaws, hasshearing edges which chop such fibrous material into fibers of shortlengths which are readily passed into the disposal outlet, and windingof the fibers about the rotor of the disposer, is avoided. The grinderof my invention will comminute even rags, paper and the like. At thesame time,.the invention provides a sturdy grinding apparatus that willpulverize hard materials such as glass without having its fiber-shearingedges dulled thereby.

A further object is to provide a garbage disposer which has dualcentrifugal pumping means on the upper and lower sides of the rotorrespectively, whereby on the upper side of the rotor, the unpulverizedmaterial is impelled outwardly against fixed grinding jaws and on theunderside, the slurry, comprising a mixture of pulverized material andwater, is impelled by centrifugal force into the disposal outlet.

A further object is to provide a disposer which in addition to the abovementioned features, is of relatively simple and inexpensiveconstruction, and very durable. To this end, the invention provides anarrangement wherein the fiber shearing mechanism is developed from acombination or" the pulp grinding jaws above the rotor and the slurryimpelling blades on the lower side of the rotor. More speficially, theinvention provides an arrangement wherein fixed pulp grinding jawsextending generally vertically in substantial parallelism to the rotoraxis, have their lower ends arranged in a common plane in a manner todefine a series of machine tool tooth shaped shearing edges, and whereinthe slurry impeller blades project beyond the rim of the rotor body,with the upper extremities of the projecting portions of the bladedisposed in a radial plane immediately below that of said saw-toothedges, and providing cutting edges which cooperate with the stationaryedges to execute a shearing action against fibers moving downwardly pastthe rim of the rotor.

Another object is to provide an improved method of fabricating thegrinder components of a garbage grinder inexpensively, to obtainaccurate but extremely hard,

2,853,249 Patented Sept. 23, 1958 -2 and long wearing grinder partshaving the combination of pulp grinding and fiber shearing structure andarrangement outlined above.

Other objects will become apparent in the ensuing specification andappended drawing in which:

Fig. 1 is a side elevation of a garbage disposer embodying my invention,with the operative mechanism shown in axial section;

Fig. 2 is a perspective view of the same with the rotor and parts abovethe plane thereof, being shown in section;

Fig. 3 is a horizontal radial sectional view of the grinder taken on theline 3--3 of Fig. 1;

Fig. 4 is a fragmentary horizontal sectional view on a larger scale,taken on the line 44 of Fig. 3 and looking upwardly to illustrate thefiber shearing and slurring impelling mechanism;

Fig. 5 is a fragmentary vertical sectional view of the same, taken onthe line 5-5 of Fig. 4; and

Fig. 6 is a fragmentary view of a preferred form of grinder toothprofile.

Referring now to the drawings in detail, I have shown, as an example ofone form in which my invention may be embodied, a garbage grinderhaving, as its main components, a motor and housing unit A; a combinedmotor dome and outlet scroll unit B; a grinder unit C; and a throat D.These parts, arranged in the order named above, are superimposed on oneanother and attached together to constitute the complete grinder unit,with the rotor unit A at the bottom and the throat D at the top,providing a means for suspending the grinder from a kitchen sink.

Referring first to the throat u-nit D, said unit comprises a cylindricalbody portion 1 which defines a throat leading downwardly from a reducedmouth 2 into the grinder unit C. Mouth 2 receives the lower end of afitting 3, the latter projecting downwardly through the drain opening inthe bottom 5 of a kitchen sink or other receptacle in which the grindermay be installed; fitting 3 have a radial flange resting on sink bottom5. The grinder is attached to an external thread on fitting 3 by meansof a coupling unit 4 which includes a ring 4a attached to the top ofthroat D by flush head screws 4b extending downwardly through the ringand into the throat D; and which further includes a collar 40 havingears projecting downwardly around the periphery of ring 4.11 and coupledthereto by set screws 4d threaded through such ears and engaging inundercut recesses in the periphery of ring 4a as shown. The faces ofthese recsss are inclined at an angle such that the pointed ends of setscrews 4d may engage them with a camming action through which, byadjusting several set screws 4d (there being three or more of the setscrews around the circumference of the coupling) the entire grinder maybe adjusted for axial alignment and fitting outlet unit B with exactnessto the sewer line.

Below its cylindrical body 1, throat D has an end portion la of enlargeddiameter within which is formed a series of saw-tooth grinder teeth 6leading downwardly to and communicating with fixed grinder teeth 7 ofgrinder unit C.

Grinder unit C is in the form of a cylindrical ring 8 having the fixedgrinder teeth 7, which is of a machine tool tooth form section, formedintegrally therein and defining the serrated inner wall thereof; andhaving an upper end fitted to the above mentioned lower end of throat Dand secured thereto by screws 9 extending from end to end through thejaw ring C. Grinder unit C also includes a grinding rotor 10 the rim ofwhich is fitted to the serrated inner wall (defined by teeth 7) of ring8. Adequate clearance is provided by the triangular openings 'end of amotor shaft 11, which is rotated by motor unit A in a counter-clockwisedirection as viewed from above (Fig. 3) and a clockwise direction asviewed from below (Fig. 4) the arrows in these two figures indicatingsuch rotation.

Rotor 10 includes a disc body 12 the periphery of which constitute therim referred to above, and has on its underside a series of radiatingslurry impellers 13 formed integrally therewith and projecting beyondthe rotor rim to provide fiber shearing blades 13a. Defined between theforward or advancing faces of shearing blades 13a and their upper faces,are shearing edges 14 (Fig. which cooperate with shearing edges 15(Figs. 4 and 5) that are formed at the lower ends of fixed grinder teeth7. As will be apparent in Fig. 4, the fixed shearing edges 15 aredisposed substantially radially, and edges 14 have a slightly swept-backinclination from true radial position, whereby the shearing actionproceeds toward the base (radially outwardly extremity) of each shearingedge 15, from the tip (radially inward extremity) thereof. Thesubstantially vertical fixed jaws 7 have substantially radial faces anddiagonal faces, the latter extending circumferentially and diagonallyoutwardly in the direction of rotation of rotor and intersecting saidradial faces to define apex edges 16. Apex edges 16, which constitutethe fixed grinding edges of grinder ring 8, are preferably disposed witha slight helical tilt as indicated in Fig. l, with an angle ofinclination extending downwardly in the direction of rotation.Consequently, there is a tendency for the material thrown outwardly byrotor 10 against fixed grinding teeth 7 to be fed by the helical tilt ofthe teeth 7, around the rim of the rotor into openings 7a.

It will now be apparent that a shearing action between the shearingedges 14 of the rotor and the fixed shearing edges will be exertedagainst fibers fed downwardly through openings 7a, in a manner to effecta chopping action on the fibers. The low inclination of the diagonalfaces of teeth 7 is such as to facilitate the outward movement of fibersinto position in front of shearing edges 15, awaiting shearing action.

Effectiveness of shearing action is obtained by the combination ofaccuracy in the dimensioning and fitting of the blades 13a to the underfaces of fixed grinder teeth 7, with only sufficient clearance to avoidthe retarding effect of frictional rubbing of the blades 13a againstsaid lower faces of the fixed grinder teeth. In this respect it will beunderstood that the clearance indicated in Fig. 5 is exaggerated for thepurpose of illustration.

The outlet scroll unit B includes a disc body 17 which provides a domefor the housing of motor unit A and has a hub 18 in which is mounted ananti-friction bearing 19 carrying the shaft 11 for free rotation ofrotor 10. Hub 18 is divided by an internal shoulder flange 20 into alower compartment which mounts the bearing 19 and an upward compartmentin which is mounted a fluid seal 21. Seal 21 is a spring loaded carbonseal of a well known manufacturer, adapted to maintain snug engagementwith the flat underface 22 of rotor 10 and snug engagement, at itsperiphery, with the cylindrical inner wall 23 defining said uppercompartment of hub 18. At the same time, the material is such as toavoid any substantial wear between its upper face and the rotor 10. Thusan effective fluid seal is maintained for a long period of operation,preventing any passage of moisture into motor unit A. This fluid sealingaction is assisted by the centrifugal pumping action of slurry impellerblades 13 which actually create a suction at the upper side of hub 18,resisting any tendency toward downward flow of any fluid in the hubregion.

The lower end face of ring 8, which is disposed in a 4. radial plane andintersects the radial faces of teeth 7 to define shearing edges 15, isindicated at 24 in Figs. 4 and 5. Outlet scroll unit B includes acylindrical lateral wall section 25, joined integrally to the peripheryof disc body 17, projecting upwardly therefrom to meet lower end face 24of grinder ring 8, and having a cylindrical inner wall 26 which isoverhung by said lower end face 24 to provide an annular space in whichshearing blades 13a rotate. Upper faces 27 of blades 13a, which areintersected by the forward faces thereof to define shearing edges 14-,are disposed in a radial plane and fitted closely to end face 24, formaximum shearing efliciency.

Grinder unit C further includes an annular integral splash guard apronor slinger ring 28 projecting downwardly from the lower face of rotor 10and defining an annular recess 29 in which is received the upwardlyprojecting upper end of rotor hub 18. This provides a further protectionto the seal from becoming clogged or contaminated with ground wasteparticles. This arrangement provides a splash-arresting seal around theseal ring 21, and the suction developed by slurry impeller blades 13constantly tends to oppose any movement of moisture inwardly past thissplash guard seal, from the scroll chamber 30 in which the slurrymixture of pulverized material and water, flowing downwardly around therim of rotor 10, is collected and guided toward an outlet 31.

As illustrated in Fig. 2, scroll chamber 30 for approximately of itslength, is of gradually increasing depth, as defined by a downwardlyslanted portion 32 of the peripheral portion of disc body 17 whichdefines the bottom of the chamber 30. This deepening portion of thescroll chamber leads to outlet 31 as shown.

In grinder unit C, the rotor 10 has on its upper side, pulp grindingblades 33 extending radially, having flat radial rear faces and serratedforward faces 34 of sawtooth form. The serrated faces 34 are inclinedoutwardly in the direction of rotation and thus exert a restrainingeffect, opposing the effect of centrifugal force in moving materialoutwardly against fixed grinder teeth 7. Forward edges 35 of serratedfaces 34 provide sharp teeth which function to engage and hold thematerial being fed outwardly to fixed grinder teeth 7, for improvedpulverizing action.

In the upper face of rotor disc 10, in the outer portion thereof andsloping downwardly to its rim, are a series of recesses 36 the forwardfaces of which are inclined upwardly in the direction of rotation as at37 to facilitate downward movement of material to these recesses, andthe rear sides of which are defined by shoulders 37a (Fig. 2) disposedin vertical, radial planes and having, at their outer extremities,secondary grinding edges 37b that cooperate with fixed grinding edges 16to effect a,

grinding action. Similarly, the outer ends of rotor blades 33 havegrinding edges 33a which cooperate with grinding edges 16 to effect apreliminary pulverizing action. In Fig. 3 at the top thereof, a smallfragment of the rotor is shown in plan, to illustrate the relationshipbetween the grinding edges 33a and grinder edges 16. The clearancebetween edges 33a and edges 16 is somewhat greater than between theedges 37b defined at the ends of shoulders 37a, whereby the coarserparticle grinding is effected by blades 33 and the finer particlegrinding by the edges 37b.

Rotor 10 has a conical hub 38 which separates and distributes outwardly,the material fed downwardly from throat D; also forms a cone into whicha blind hole is drilled and tapped which eliminates corrosion which willfreeze the rotor-shaft 11 into the rotor 10.

Motor unit A includes the motor, the armature of which is visible at 39,and a casing 40 the upper end of which is fitted to the lower end ofscroll body 25. Long screws 41 are extended full length through lateralwall of motor casing 40 and the lateral wall section 25 of unit B, andthreaded into the grinder ring 8 as indicated in Fig. 1, thus securingthese several sections of the grinder in assembly. The mating ends ofthese sections are properly flanged, a indicated, for pilotinginter-engagement such as to establish the coaxiality of these parts, andto effect a seal between them. If necessary, although not shown, gasketsmay be interposed between the adjoining ends of throat 1, ring 8 andscroll body 25, in order to attain a liquid tight connection. Thusthereis defined, between throat D, grinder ring 8 and rotor 10, agrinding chamber 42 which is liquid tight except for the escape openings7a, and there is defined between the lower side of rotor and scroll unitB, outlet scroll chamber 30 leading to outlet 31.

Accuracy and durability in the grinder components in cluding the ring 8and the rotor 10 is obtained by a process of fabrication wherein theseparts are first formed as sand castings, using highly compacted molds offine sand, shaped in accurate patterns and baked to an adequate degreeof hardness and form stability; machining the end faces and upper faces27 of shearing blades 13a to an accurate fit within cylindrical innerwall 26 of lateral body 25 of outlet scroll unit B and to provide theclose accurate clearance between the upper faces 27 and the lower endface 24 of ring 8, which is likewise machined. The rim of the disc bodyof rotor 10, and the underface 22 thereof, may likewise be machined. Theupper end face of ring 8 may likewise be machined for proper close fitbetween throat unit D and motor casing A. After machining, these partsare flame hardened so as to harden their cutting edges without creatingany distortion in the castings. This flame hardening is applied toshearing blades 13a, to the grinding teeth 7, and to the grinding blades33. Thus there is imparted to the cutting edges, long life wear suchthat the cutting edges do not require re-sharpening.

Referring now to Fig. 6, the preferred form of grinder tooth sectionshown in that figure, which, like Fig. 4, looks upwardly past theleading edge of a shearing blade 13a at the lower end face 24 of grinderring 8, tooth section being shown in end profile. The forward faces ofthe teeth, instead of being disposed in radial planes as previouslydescribed, are of semi-cylindrical curvature, so that the cutting edgesa are semi-circular. The slanting rear faces 43 of the teeth are tangentto the curved forward faces, at the base of the latter, and instead ofintersecting the outer extremities of the curved faces to define thevertical cutting edges 16a, slanting faces 43 intersect segmentalcylindrical faces 44 to define lands which are fitted closely to the rimof the rotor disc 12.

The advantage of this improved tooth profile arises from the fact thatthe fibers, sheared near the outer extremities of cutting edges 15a at16a will have little tendency to pack in the base area of the groovedefined between succeeding teeth, as they do have in a saw-tooth profilesuch as is shown in the other figures. Instead, they will curl aroundthe curved contour of cutting edges 15a and even past the points oftangency with slanting faces 43, if necessary, in order to work theirway out of the pocket between the teeth and gradually feed downwardlythrough opening 7a.

It will now be apparent that blades 33 on the upper side of rotor 10 dodouble duty as centrifugal pumping blades which urge the raw materialoutwardly against grinding teeth 7 and which have at their outer endsthe cutting edges 33a, cooperating with fixed grinding edges 16 for theprimary pulverizing action. Again, there is provided, in rotor 10, thesecondary grinding edges 37a, coacting with fixed grinding edges 16 forthe finer pulverizing at a lower level, prior to passage of thepulverized material downwardly through opening 7a into the outlet scrollchamber 30.

Below the rotors, there are the slurry impeller blades 13 having theprojecting tips 13a which constitute the shearing blades coacting withshearing edges 15 for chopping into short lengths, fibrous materialwhich is urged downwardly into openings 7a by the downward flow ofpulverized material. The blades 13 also function to create, in outletscroll chamber 30, by centrifugal force, a pumping action, which inconnection with the gradually increasing area of chamber 30 approachingoutlet 31, develops the pumping action which has two useful effects,namely: (a) to facilitate the downward flow of material past the rim ofrotor 10 and (b) to create, between scroll body 17 and the lower side ofrotor 10, adjacent hub 18, a region of lowered pressure which opposesany tendency for liquid to pass inwardly toward fluid seal 21, thusreinforcing the action of seal 21 in preventing any escape of moisturefrom the outlet chamber 30 into the motor unit A.

I claim:

1. In a waste disposer: a housing; a rotor mounted therein for rotationon the major axis thereof, said rotor having a circular rim, having aplurality of impeller blades integral with and projecting downwardlyfrom the lower face thereof, said blades extending generally radiallyfrom a diameter inwardly of said rim to said rim and having integral tipportions constituting shearing blades projecting beyond said rim andprovided with upper faces disposed substantially in a radial plane, saidrotor further having grinder blades integral with and projectingupwardly from the upper face of said rotor, said grinder bladesextending generally radially to said rim and having grinding endssubstantially flush with said rim; said housing having internalserrations in a continuous array about the circumference thereof andextending generally parallel to said major axis from the plane of theupper faces of said shearing blades to a substantial height above theupper face of said rotor and above said grinder blades, said serrationsdefining fixed grinder teeth extending from the upper extremities ofsaid grinder blades substantially to the plane of the upper faces ofsaid shearing blades and defining waste-conducting passages extendingfrom above said grinder blades downwardly past said rim to said plane,for feeding ground waste downwardly past said rim to said shearingblades, said fixed grinder teeth being of saw-tooth cross section in aplane normal to said major axis, and having substantially radiallydisposed forward faces toward which said rotor revolves, said fixedgrinder teeth having lower ends overhanging said shearing blades anddisposed substantially in a radial plane closely adjacent the upperfaces of said shearing blades, said lower ends having, as the loweredges of said radially disposed forward faces, shearing edgescooperating with the upper edges of said shearing blades for shearingfibrous waste passing downwardly past said rim, and said fixed grinderteeth having rear faces that are slanted outwardly in the directron ofrotation of said rotor to the outer extremities of said forward faces,so as to facilitate outward movement of waste from said rotor into saidwaste conducting passages; said housing defining an annular wastedisposal space therein directly below said rotor, in which said shearingblades are adapted to revolve, and a disposal outlet communicating withsaid disposal space, said impeller blades and shearing blades having acentrifugal pumping action impelling waste into said outlet.

2. A disposer as defined in claim 1, wherein said rotor has in its upperfaces, recesses opening through said rim and of gradually increasingdepth from their inner extremities to said rim, with downwardly andoutwardly sloping bottoms.

References Cited in the file of this patent UNITED STATES PATENTS2,322,058 Powers June 15, 1943 2,442,812 Jordan June 8, 1948 2,476,630Schindler July 19, 1949 2,577,152 Powers Dec. 4, 1951 2,594,250Tranbarger Apr. 22, 1952 2,682,376 Frank June 29, 1954

